However there is also ... /Contents/MacOS/ with a slightly larger (66k) file Sage
If I run that rather more happens, a new browser page (google Chrome) pops up (The Sage server is currently starting ...) and I get in the terminal window:

Comments

My 10.7 machine also doesn't have `/usr/local/lib/libreadline.5.2.dylib`, so although the download is far too slow for me to try it, I'm sure this error is because of that. Can you put more details so that we can see where his reference is from? In theory, Sage creates its own libreadline and should use that.